1. Field of the Invention
The present invention relates to a recording tape cartridge rotatably accommodating a single reel, around which a recording tape such as a magnetic tape is wound.
2. Description of the Related Art
Conventionally, magnetic tape cartridges have been known in which a magnetic tape, which is used as a data recording/playback medium of a computer or the like, is wound on a single reel, and the reel is accommodated within a case. A leader member, which is a leader pin, a leader tape, or a leader block, for example, is provided at the distal end of the magnetic tape. A pull-out means provided at a drive device pulls out the leader member from an opening of the magnetic tape cartridge, and the magnetic tape fixed to the leader member is wound onto a take-up reel of the drive device.
A reel gear is carved in a ring shape at the center of the bottom surface of the reel which emerges from an opening formed in the bottom surface of the magnetic tape cartridge. Due to a driving gear, which is provided at a rotating shaft of the drive device, meshing with the reel gear, the reel is driven to rotate. Further, due to the reel of the magnetic tape cartridge and the take-up reel of the drive device being rotated synchronously, data can be recorded onto the magnetic tape or data recorded on the magnetic tape can be played back.
A large amount of information can be recorded in this magnetic tape cartridge, although little space is needed to accommodate the magnetic tape cartridge when it is stored. As shown in FIGS. 10 through 12, the position of the opening of the magnetic tape cartridge and the type of door for opening and closing the opening differ in accordance with the type of the leader member. Namely, in the case of a leader pin 108, as shown in FIG. 10, an opening 104 is formed in a side wall 102A of a case 102 which side wall 102A is parallel to the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow A). The opening 104 is opened and closed by a door 106 which slides in the same direction as the loading direction.
However, if the opening 104 is provided at the side wall 102A of the case 102 in this way, the pull-out means of the drive device must pull the leader pin 108 out from the left-right lateral direction of the case 102 (i.e., non-rectilinearly). Thus, space for the pull-out means to move around the case 102 must be ensured in the left-right lateral direction of the case within the drive device, and the mechanism for moving the pull-out means around (i.e., non-rectilinearly) becomes complex. In other words, the drawback arises that the drive device becomes large. Moreover, there is the problem that the path along which a magnetic tape T is pulled out becomes long.
Further, in the case of a leader tape T, as shown in FIG. 11, an opening 116 is formed in a front wall 114A of a case 114 which front wall is orthogonal to the direction of loading the magnetic tape cartridge into a drive device (the direction of arrow A). A door 118, which opens and closes the opening 116, is a pivoting-type door which pivots toward the front around a shaft supported in a vicinity of a corner of the case 114. However, if the opening 116 is provided at the front wall 114A of the case 114 in this way, although there is no need for the pull-out means of the drive device to move non-rectilinearly, the door 118 opens over a wide area toward the front. Therefore, space must be ensured within the drive device such that nothing interferes with the door 118 when the opening 116 is to be opened. In short, a drawback arises in that the drive device becomes large.
Moreover, in the case of a leader block 126, as shown in FIG. 12, an opening 124 is formed by diagonally cutting off a corner portion of the front side of the case in the direction of loading the magnetic tape cartridge into the drive device. The opening 124 is opened and closed directly by the leader block 126. However, if the opening 124 is opened and closed by the leader block 126 in this way (namely, if the leader block 126 also functions as the door for opening and closing the opening), a problem arises in that it is easy for the leader block 126 to become scratched or dirtied. Specifically, the leader block 126 fits together with a reel hub 130 of the drive device and forms a portion of the reel hub 130. Thus, if a scratch is formed in or dirt adheres to the leader block 126, even if the scratch or dirt is a scratch or dirt which is not problematic when the leader block 126 is ordinarily used as the door, it may become difficult for the leader block 126 to fit-together with the reel hub 130, and there is the possibility that problems in the moving of the magnetic tape T may arise.
Further, since the leader block 126 forms a part of a winding surface for winding the magnetic tape T, the above-described damage or contamination may damage the data recorded on the magnetic tape T or may create damaged areas on the magnetic tape T where data cannot be recorded.
Furthermore, since the leader block 126 is merely anchored at the edge of the opening 124, the leader block 126 may come off when the case 122 is dropped. Moreover, since the size of the leader block 126 is larger than the size of the leader pin, many constraints are imposed on the form of the case 122.